The present invention relates to seating and the like, and in particular to a convertible inner shell for constructing both armed seats and armless seats.
Commercial seating, such as that used in offices, transportation terminals, lounges, industry and the like is typically offered in both armed and armless versions to accommodate a wide variety of different applications. When the seating has a two-part shell construction, such as that disclosed in U.S. Pat. No. 3,669,499, two different inner shell members are usually required to construct the armed and armless versions of the seat. In the armed seat, the inner shell contains notches in its peripheral edge through which the ends of the seat arms extend. In the armless seat, the inner shell has a substantially continuous, or uninterrupted peripheral edge, so that the cushions mate with the inner surface of the outer shell.
In view of the above, it would clearly be advantageous to have a single inner shell construction, which is capable of being used to make both the armed and the armless versions of the seat. This would reduce parts inventory, handling costs, manufacturing and tooling costs, assembly line space requirements, as well as other similar factors which add to the overall construction cost of the seating. Also, it would be beneficial to provide such an inner shell which could be easily and quickly converted from one version to the other.
Another problem experienced heretofore with seating inner shells, is that when an armed inner shell is upholstered, the pockets that are formed in the edges of the cushions do not mate closely with the seat arm, thereby forming rather unsightly gaps between the cushions and arms. Further, it is extremely difficult to obtain a uniform pocket size from one cushion to the next. As a result of these two factors, it has been nearly impossible to consistently maintain clean, tight-fitting upholstery lines around the ends of the seat arm. Although special padding and custom fitting can be used to alleviate these gaps and voids, this is a very time consuming and expensive remedy, which is not practical for mass production manufacturing operations.
Although the Steelcase-Strafor '451 shell includes a knockout plug which adapts the inner shell for both armed and armless chairs, it does not alleviate the problem of consistently forming a pocket in the cushion that fits tightly with the seat arm. Furthermore, the removal of the plugs from the inner shell requires the use of a tool, is a rather tedious and time consuming task, and the tab stubs tend to hamper the formation of consistently tight arm pockets.